Safety device for intermittently operated machinery



Nov. 10, 1942 D. RUSCH 2,301,817

SAFETY DEVICE FOR INTERMITTEN'I'LYOPERATED MACHINERY Filed Feb. 12, 19422 Sheets-Sheet 1 will NOV. 10, 1942. RUSCH 2,301,817

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5 i 4 7 h m I 47 l I I I up All my 1: J a a 3 Patented Nov. 10, 1942SAFETY DEVICE FOR INTERMITTENTLY OPERATED MACHINERY David Busch,Chicago, Ill., assignor to Benjamin Electric Mfg. Company, Des Plaines,11]., a. corporation of Illinois Application February 12, 1942, SerialNo.430,676

12 Claims.

This invention relates to safety devices for intermittently operatedmachinery and particularly for punch presses, or the like.

In feeding material to punch presses and like intermittently operatedmachines, it is necessary said moving parts at the time the press iscaused to operate, various safety devices have heretofore been proposed.Some of these safety devices employ control levers or handles located ina position of safety and so interconnected, as by rockably secured linkarms, that both handlesmust li be depressed in order to trip the clutchmechanism. If but one handle is depressed, the rockably secured link armwill rotate about its center and not trip the clutch.

However, it has been found that prior devices 9 of this character areobjectionable, in that, in order to speed up their rate of production,onerators will secure or tie down one of the control handles in adepressed position, so as to permit single-handed operation of thecontrol simply 1:

by depressing the other handle. With such an arrangement, the operatorthen proceeds to feed the material to the press with the free hand andit is possible for the press to be. tripped while this free hand is in aplace of danger. of safety device does not therefore entirely remove thehazard of injury to the operators hands.

To compel the operator to remove his hands to a position of safety andto defeat any attempt on his part to render the safety deviceineffective as above indicated, the present invention proposes atripping mechanism operated by two handles and so constructed that bothmust be simultaneously depressed before the tripping mechanism may becaused to operate. therefore, an object of the present invention toprovide a tamper-proof punch press tripping mechanism which may notreadily be altered to This type It is,

permit operation in other than its intended manner. V

The present invention also provides a control unit of simple and compactconstruction wherein all of the component parts subject to wear, areenclosed in a unitary housing which may beinstalled or removed as aunit.

A further object of the present invention is to provide a punch presstrip control embodying a minimum number of parts, which is positive inaction and is easy to assemble and maintain.

Other objects and advantages will appear from a consideration of thefollowing detailed specification. For a more complete understanding ofthis invention, reference may now be had to the drawings, in which:'

Fig. 1 is a side elevation of one embodiment of the present invention;

Fig. 2 is a top plan view of the embodiment illustrated in" Fig. 1; v

Fig. 3 is an enlarged detail vertical sectional View partially inelevation of the safety control unit of the present invention;

Fig. 4 is a horizontal sectional view taken along a line substantiallycorresponding to line 4-4 of Fig. 3;

Figs. 5, 6 and 7' are changed position views similar to Fig. 3, butsomewhat reduced in size;

Fig. 8 is'a detail perspective view of the operating'carriage employedin the'present invention;

Fig. 9 is an enlarged perspective View of one of the slides, two ofwhich are employed; and,

Fig. 10 is a detail perspective view of one of the latch rollers, two ofwhich are employed. Referring to the drawings in detail, the embodimentillustrated comprises spaced operating handles l and 2 which may bemounted on opposite sides of an upright punch press frame 3, in themanner shown in Figs. 1 and 2. These operating handles may be supportedupon a common connecting shaft 4.

Handle I may be securely afiixed to shaft 4 by means of locking capscrew 5. The handle 2 is rotatably mounted on horizontal shaft 4 at theend opposite the handle I and kept from slipping longitudinally off theend of the shaft by means of a washer and cotter pin arrangement 5. Ashort arm 1 may also be firmly secured to the shaft 4-adjacent handle 2,as by a suitable looking cap screw 8, so that downward manipulation ofhandle I will cause a corresponding movement of arm 1.

The outer end of the short arm 1 is provided with a nut 9 which ispivotally mounted thereon and engages the threaded lower end of anadjustable link 10. A similar nut H is intermediately located on thehandle 2 and engages the threaded lower end of a similar link l2.

With the above arrangement, it will be apparent that downward movementof the handle I causes rotation of shaft 4 and a corresponding downwardmovement of short arm I, with the result that link In is drawndownwardly. Similar downward movement of handle 2 causes link 12 to movedownwardly. Both links and their connected handles are normally retainedin an upward position by resilient means hereinafter de scribed.

The details of the control unit are shown in Figs. 3 to inclusive. Thisunit includes a rear base plate l3, a housing member I4 and a frontcover platel5. The rear base plate [3 is provided with lugs [6 throughan opening in which suitable fastening screws may extend to secure theunit to the side of a punch press frame, or the like. This rear baseplate is also provided with opposed projections I1 and I8 of reducedthickness and having arcuate slots l9 and 20, respectively. Theprojections I 'l and [8 being of reduced thickness are somewhat spacedfrom the rear surface of the rear base plate I3 to .provide room forbolt fastening means as shown.

The housing member M is preferably in the form of an inverted U toprovide a top portion 2'! and opposed depending leg portions 22 and 23.To this is affixed an outer cover member [5 which is peripherally shapedto conform to the outer surface of the housing member. The cover memberl3 and the housing member I 4 have oppositely disposed lugs 24 and 24ato accommodate fastening bolts 25. These bolts 25 may extend through thearcuate slots 19 and 23 and be secured in place by nuts 25a. Thispermits the entire unit to be bodily adjusted about its central axis andthen securely locked in a selected position.

The rectangular inner area of the above housing is defined byvertical-side walls and is adapted" to accommodate and guide avertically reciprocatable carriage 26 'shown'in'detailin Fig. 8. Thiscarriage 26 comprises a central support bar 2! having an upstandingthreaded portion 28 which may extend through an opening 29 in the top 2|of "the housing I 4. This carriage has a frame, preferably formed ofsheet metal sections 33 and 3| which are secured together and to thecentralsupport bar by means of spaced rivets 32 extending therethrough.

The entire carriage, including the central support bar, upwardlyextending threaded shaft and the stamped sections is a single member.

The spaced axially extending openings left in the carriage on each sideof the central supporting bar 21 accommodate opposed slide blocks 33shown in detail inFig. 9. Two of these slide blocks are used in thepresent invention and are a sliding fit within the carriage. They areseparately operable for vertical sliding movement in these openings.Each comprises an elongated member having a ratchet-receiving recess 34adjacent its upper end which is shaped to accommodate a flat ratchetplate 35. This plate is rounded at both ends and adapted to be insertedinto the ratchet opening for limited movement therein. The ratchet plateis preferably formed of hardened material more readily to resistwear.

A pair of resilient compression springs 36 are mounted under eachratchet plate and bear thereon. to resiliently retain the plate in anupward position in its slot. Retaining pins 31 are provided oneach slideblock adjacent the outer end of the ratchet plate and serve to preventplate during-ratchetoperatiOn thereof. Each of the slide blocks 33 isalso provided with latch races 33 and 39, the course of each of which isinterrupted by said ratchet plate 35.

In assembly, the slide blocks are placed in the carriage with theratchet plates each facing the central support bar 21 for verticalsliding movement in their respective apertures.

The central supporting bar is provided with recesses 43 and 4| disposedon opposite sides thereof and in which are located latch rollers 32-42.When assembled, these latch rollers lie opposite the races 38 and 39.

With the unit assembled, ratchet-retaining bolts 53 and 34 may beinserted through suitable openings 33, 45a in the top 2! of the bodyportion M and springs 36-43 may be placed about each bolt to bearagainst the inner top surface of the block and resiliently retain it inan upward position. The compression of the springs is adjustable byrotation of retaining bolts 43 and 6 2 to vary the position of nuts 41thereon.

The upwardly extending threaded portion 28 ofthe carriage passes throughopening 29 in the housing and the entire carriage is resilientlyretained in place by means of a coil spring 48. This shaft 28 may besecured by any suitable means, as by the adjustable link 49 to theclutch mechanism trip lever 53, operation of which causes the trip ofthe punch press to release the clutch and permit operation of the press.

In operation, with the control unit instahed on a punch press asindicated above and with the press ready to operate, the operator firstplaces his hands, one on each of the handles i and 2, and simultaneouslymoves these handles downwardly. This causes links Ill and I2 withconnected ratchet slides 33 to also move downwardly and the ratchets ofthese slides engage the latch rollers 42, so that carriage 26 is moveddownwith the ratchets. Through threaded stem 23, link 50 is thus moveddownwardly to trip the press. Fig. 6 indicates the relative position ofthe parts during such downward movement, the direction of movement ofthe parts being shown by arrows.

Obviously wtih the above arrangement, the operators hands must be out ofthe path of the machines movement before the press is tripped. Shouldthe operator fail to press both handles, then the parts assume therelative position indicated in Fig. 5 where one of the ratchet slideblocks 33 is shown moved downwardly and the latchroller 42 is shownlaterally displaced into the race 39 to evade the ratchet plate 35whereby the carriage 25 remains stationary. The latch rollers wouldlikewise be displaced in the opposite direction upon downward movementof the opposite ratchet slide block.

The above result could perhaps be achieved with a ratchet block assemblywhich would not include resilient means for urging the ratchet plateupwardly in its notch. However, in order to permit return of the slideblocks to their uppermost position after the trip has once beenoperated, it is necessary to provide means whereby the ratchet platesmay be permitted toyield and move around the latch rollers during theirupward return movement. This is accomplished in the present embodimentby the provision of springs 36, one set of which is shown compressed inFig. 7, so that ratchet plate 35 may move upwardly beyond the latchrollers 42.

Any attempt to fasten one of the handles in a downward position andmanipulate the control by one hand while feeding the press with theremaining free hand would be of no avail, inasmuch as simultaneousdownward movement of both handles is required to trip the press. Withone handle secured downwardly, manipulation of the other handle wouldmerely cause lateral displacement of the latch rollers without anycorresponding downward movement of the carriage.

While particular embodiments of the invention have been shown, it willbe understood, of course, that it is not desired that the invention belimited thereto since modifications may be made, and it is, therefore,contemplated by the appended claims to cover any such modifications asfall within the true spirit and scope of the invention.

Having thus described the invention, what is claimed and desired to besecured by Letters Patent is:

1. A clutch controlling device comprising a longitudinally movablecarriage, laterally displaceable means supported on said carriage foractuation thereof, and oppositely disposed ratchet members forsimultaneously engaging said laterally displaceable means to actuatesaid carriage, said ratchet members being ineffective to move saidcarriage except during simultaneous movement of said ratchet members,neither of said ratchet members being effective to move said carriagewhen the other ratchet member is in the position to which it is moved inits normal actuating movement.

2. A safety control for punch presses and the like comprising a housing,a carriage slidably mounted in said housingfor operating connection tothe usual clutch tripping mechanism of a press, independently operableratchet members slidably fitted in said carriage, and common latch meanssupported on said carriage for actuation thereof and engageable bysimultaneous movement of said ratchet members, said ratchet members beinso related to said common latch means that simultaneous movement thereofcauses 5 movement of said carriage while other than simultaneousmovement causes displacement of said common latch means to free saidratchet members therefrom, neither of said ratchet members beingeffective to move said carriage when the other ratchet member is in theposition to which it is moved in its normal actuating movement.

3. A control mechanism for operation of a clutch tripping devicecomprising a movable carriage effective upon bodily movement to tripsaid clutch, a displaceable force-transmitting means associated withsaid carriage, and independently operable means to actuate said carriagethrough said force-transmitting means upon simultaneous movement of saidindependently operable means, said force-transmitting means serving toprevent movement of said carriage by said independently operable meanswhen movement of said independently operable means is not simultaneous,neither of said independently operable means being effective to movesaid carriage when the other independently operable means is in theposition to which it is moved in its normal actuating movement.

4. In a punch press trip mechanism wherein simultaneous movement of twooperating levers is a prerequisite to tripping action, the combinationwith a movable trip member for tripping the clutch of a press, of acarriage connected to said movable member, a latch mounted on saidcarriage, and opposed ratchet members having resiliently mountedlatch-engaging portions to engage said latch so that simultaneousdownward movement of said ratchet members moves said latch and saidcarriage to trip said movable trip member but independent movement ofeither of said ratchet members causes displacement of said latch anddisengages said carriage from said ratchet members, neither ofsaidratchet members being effective to move said carriage when the otherratchet member is in the position to which it is moved in its normalactuating movement.

5. In a punch press trip operating mechanism, a movable member fortrippin the clutch of a press, a carriage connected to saidmovablemember, latch means mounted for lateral movement in said carriage,spaced independently operable latch-engaging members disposed onopposite sides thereof, and operating handles linked to saidlatch-engaging members whereby simultaneous downward movement of both ofsaid handles causes downward press tripping movement of said carriagewhile individual movement of said handles causes lateral displacement ofsaid latch to remove it from operating engagement with said members,neither of said latch-engaging members being effective to move saidcarriage when the other latch-engaging member is in the position towhich it 1s moved in its normal actuating movement,

6. A control mechanism for tripping the clutch of a punch presscomprising an actuated member whose movement causes operation of thepress, spaced co-operating independently movable actuating members forcontrolling the movement of said actuated member, force-transmittingmeans mounted upon said actuated member and laterally displaceablethereon, said force-transmitting means being disposed between saidspaced actuating members and capable of force-transmitting co-operationtherewith for movement of said actuated means upon simultaneous similarmovement of said actuating means, neither of said actuating means beingeffective to move said carriage when the other actuating means is in theposition to which it is moved in its normal actuating movement.

7. A trip mechanism for controlling the tripping of a press comprisingan actuated member whose advance movement causes operation of the press,two co-operating independently movable actuating members for controllingthe movement of said actuated member, movement-directing means formounting said actuated member for advance movement efiective to trip thepress and for lateral movement ineffective to trip the press, andmovement-directing means for mounting each of said actuating members foreffecting lateral movement of said actuated member ineiiective to tripthe press when only one of said actuated members is operated and foreffecting advance movement of said actuated member effective to trip thepress when both said actuating members are operated simultaneously,neither of said actuating members being effective to move said carriagewhen the other actuating member is in the position to which it is movedin its normal actuating movement.

8. A guide, a carriage movable in said guide, latch means movablymounted on said carriage for movement transversely of the movement ofthe carriage, two manually operable independently movable actuatingmembers reciprocably mounted on said carriage for movementlongitudinally of the carriage movement and engageable with said latchmeans to exert opposing force components thereon transverse to themovement of the carriage and. also concurrent force components thereonlongitudinally of the movement of the carriage whereby when saidactuatin means are moved to act simultaneously on the latch means thetransverse components will latch the carriage to both actuating meansand the longitudinal components will cause movement of the carriage andwhereby when one of said actuating members acts in advance of the otherthe latch means will be moved to nonlatching position with respect tosaid advance actuating member, neither of said actuating members beingeffective to move said carriage when the other actuating member is inthe position to which it is moved in its normal actuating movement.

9. A guide, a carriage movable in said guide, latch means movablymounted on said carriage for movement transversely of the movement ofthe carriage, two manually operable independ ently movable actuatingmembers reciprocably mounted on said carriage for movementlongitudinally of the carriage movement and engageable with said latchmeans to exert opposing force components thereon transverse to 'themovement of the carriage and also concurrent force components thereonlongitudinally of the movement of the carriage whereby when saidactuating means are moved to act simultaneously on the latch means thetransverse components will latch the carriage to both actuating meansand the longitudinal components will cause movement of the carriage andwhereby when one of said actuating members acts in advance of the otherthe latch means will be moved to nonlatching position with. respect tosaid advance actuating member, said actuating members being latchablewith respect to said latch means in only one direction of reciprocationof said actuating members on said carriage, neither of saidactuatingmembers being efiective to move said carriage when the otheractuating member is in the position to which it is moved in its normalactuating movement.

10. A ratchet actuating member for a safety punch press control deviceor the like comprising, an elongated member having an opening extendinginto its interior, and a ratchet receiving notch adjacent one end, aratchet the end of which seats and pivots in the bottom of said notch,resilient means for normally urging said ratchet to one side of saidnotch, and a ratchet retaining peg extending transversely of theswinging end of the ratchet to retain said ratchet in place when it ismoved to the opposite side or" said notch.

11. An actuating member for a safety punch press trip control comprisingan elongated slide block having grooves in one surface thereof, awedge-shaped notch intersecting said grooves, a latch engaging ratchetmember movably secured said notch, and resilient means to urge saidratchet member to one side of said notch whereby a latch may be actuatedby movement of said actuating slide block in one direction and may bereleased through said resilient means upon movement of said slide blockin the opposite direction.

12. Means for actuating a safety punch press trip control devicecomprising a guide block, an elongated slide block reciprocably mountedthereon, said slide block having an opening extending longitudinally ofits movement, means for yieldingly securing said slide block to saidguide block comprising an anchor bolt extending into said opening and aspring in said opening surrounding said bolt, said slide block having anotch in one side thereof, a ratchet member pivotally mounted in saidnotch, and resilient means urging said ratchet member toward one side ofthe notch.

DAVID RUSCI-I.

